The effective screening, diagnosis and treatment of cervical intra-epithelial neoplasia in the developed world has reduced the mortality due to cervical cancer enormously. Tragically, in the developing world where resources are not available this disease is the leading cause of cancer death. As part of the new managedhealth reality in the developed world there is an important need for improved screening and detection methods for cervical intra-epithelial neoplasia that are both sensitive and cost-effective. Optical diagnostic technologies have the potential to address both of these issues, by providing accurate, objective and instantaneous point of care diagnostic and screening tools. However, the connection between these optical signatures and the underlying morphology and biology arenot well understood. We believe that the full potential of these technologies can be achieved only if this connection is understood. The goal of Project lof this Program Project is to develop quantitative models that explicitly describe this relationship. We believe that developing spectral analysis tools that relate spectral changes to specific molecular and morpbologic alterations will yield the most robust diagnostic algorithms and will also provide the most useful prognostic information. In this Program Project, Project 1 will provide and validate these models. They will be used in the large screening and diagnostic trials of Project 2 and the randomized clinical trial in Project 3 to test this hypothesis. To our knowledge, this represents the largest trial of an optical technology with an objective gold standard and a statistically justified sample size. We believe that these steps are crucial to achieve the potential of optical technologies in both the developed and developing world. The specific goals of this proposal are: (1) To conduct a series of high resolution optical imaging and spectroscopy studies to elucidate the biological and morphological basis for the differences between the fluorescence and reflectance spectra of normal and neoplastic cervical tissue in vivo; (2) To use tissue-engineered constructs of normal and neoplastic cervix to test analytic models of tissue spectra and to explore the effects of epithelia/stromal interactions on fluorescence and reflectance spectroscopy and multispectral imaging; (3) To develop and test analytic and computational models that describe tissue optical properties and fluorescence and reflectance spectra in terms of tissue biochemistry, morphology and architecture; (4) To develop and test robust strategies to fit measured tissue spectra to analytic models to extract concentrations of chromophores and morphologic structure from fluorescence and reflectance spectra; (5) To collaborate with Core B and use the data from the large screening and diagnostic trials in Project 2 to develop diagnostic and screening algorithms based on molecular and morphologic changes extracted from optical spectra to improve optical diagnostic algorithms for cervical pre-cancer; (6) To use analytic and computational models to design fiber probes to separately collect fluorescence from epithelium and stroma and further improve optical diagnostic algorithms, testing these approaches in tissue-engineered constructs and freeze-trapped samples; (7) To develop analytic and computational models to design variable field of view imaging systems to separately collect fluorescence from epithelium and stroma and further improve optical diagnostic algorithms, testing these approaches in tissue-engineered constructs, freeze-trapped samples and excised biopsies.